1. Field of the Invention
The present invention relates to methods of cooling printed circuit boards in an enclosure, and more particularly relates to cooling blade servers in a rack-mounted enclosure using heat transfer through surface contact and forced air.
2. Description of the Related Art
A blade server is a single circuit board populated with components, such as processors, memory, and network connections that are usually found on multiple boards. Blade servers are designed to slide into enclosures. Blade servers are more cost-efficient, smaller, and consume less power than traditional rack-based servers.
Current blade server designers face many design challenges. One of the key challenges is minimizing overall design costs. Another is keeping blade server electronic components cool and within their operating specifications. Yet another is maintaining accessibility (easy removal and reattachment) of the individual blade server from a housing unit. A successful blade server design must address these critical issues, that is, heat, accessibility, and costs.
A popular cost-saving blade server design approach utilizes Commercial Off-the-Shelf (COTS) products, such as the industry standard MicroATX, ATX, BTX, EATX form-factor motherboards. Unfortunately, the COTS design approach has many inherent design deficiencies. In reality, most COTS motherboards are not designed to fit into slim-style, height-restricted blade enclosures. Rather, they are designed for spacious computer enclosures with plenty of headroom for the component cooling devices. In addition, utilizing COTS motherboards in blade server designs hinders blade accessibility due to non-uniform I/O connector height. Nevertheless, COTS motherboards are readily available and can be purchased cheaply on the market. The cost saving is a very compelling reason for blade designers to utilize COTS motherboards in their blade server designs.